Added point visualization

Added “rules” to analytics tab, as shown in most recent Dropbox
mockups. Radio buttons are still nonfunctional, and need to be linked
to student data.

### Screenshot
![ios simulator screen shot dec 3 2013 9 52 02 am](https://f.cloud.github.com/assets/804390/1664735/7c42073c-5c2b-11e3-90de-ca89ac177b06.png)

### Reference Mockup
![screen shot 2013-12-03 at 6 22 53 am](https://f.cloud.github.com/assets/804390/1664722/6690bf14-5c2b-11e3-8566-b43274b07655.png)